Windows/Mac: If your iTunes library is in pathetic shape with mismatched tags, missing album art, and duplicate tracks, TuneUp is a handy tool that will fix it all for you automatically—and it's on sale for 40% off right now.

We've shown you how to whip your music library into shape using free (or mostly free) tools, but if you want to get it done without the hassle, TuneUp is one of your best options. It's very easy to use, and most of our readers who've used it love it, so it's well worth its one-time price of $30 (down from $50) or year subscription for $24 (down from $40). If you have rare or unreleased tracks, it'll probably do more harm than good on those—and some of you are mentioning in the comments that you've had problems—so try it in small batches instead of letting it run free over your entire library.